The Product Backlog refinement should not take more than what percentage of the developers' time?

The recommended percentage of the developers' time dedicated to Product Backlog refinement is 10%. This is based on Scrum guidelines which suggest that refinement should take no more than a small portion of the overall time available in a sprint.

Aiming for around 10% helps ensure that the development team has adequate time to focus on their development work while still allowing for the necessary preparation and clarification of the Product Backlog items for upcoming sprints. This balance is crucial to maintain efficient workflow and keep the team well-informed about the items they must deliver, while avoiding excessive backlog management that could detract from actual development tasks.

Keeping the refinement effort within this limit supports continuous improvement of the backlog, enhances clarity and understanding, and allows for effective prioritization of work without overburdening the development team. Adhering to this recommendation is a best practice in Scrum to promote a healthy and productive team dynamic.